Algorithm for calculating the optimal value of the field substation voltage

Abstract

The article is devoted to improving the energy efficiency of mechanized mining by selecting the optimal voltage level at the field substation, which provides the required optimization criterion. An unbranched line extending from the field substation, which supplies an arbitrary number of electrical complexes of producing wells, is considered. It is shown that these complexes can contain both submersible centrifugal pumps and rod borehole pumping units driven by asynchronous motors. Mathematical models of electrical complexes of producing wells are nonlinear and are described by high-order differential equations. Therefore, the problem of finding the optimal voltage level of a field substation can only be solved using numerical methods. An algorithm for calculating the optimal voltage value is developed, taking into account the technological features of mechanized oil production. It is a search algorithm that contains three internal cycles: voltage variations at the asynchronous motor farthest from the field substation, sorting out the nodes of the outgoing line, and equalizing the voltage at the nodes when the load of the electrical complexes of the producing wells changes. Well-known analytical expressions are given for calculating the active, reactive and full load of step-up and step-down transformers used in the considered electrical complexes, as well as power losses on these elements and on air and cable lines. A distinctive feature of the presented algorithm is the calculation of the speed of submersible and ground asynchronous motors when the supply voltage changes, taking into account the mechanical characteristics of centrifugal and plunger pumps. An example of calculating the optimal voltage value of a field substation feeding a hypothetical outgoing line with three nodes is given. It is noted that the developed algorithm is a reflection of the method of choosing the optimal voltage of the field substation. Moreover, this algorithm can be adapted to any outgoing line, no matter how complex and branched it is.